Cooking time adjusting arrangement for use in electronic oven

ABSTRACT

A cooking time adjusting arrangement for use in an electronic oven is disclosed. The arrangement includes a display device representing a plurality of data such as various menus, the number and/or quantity of each of the menus with or without cooking times, setting of a timer device to operate the electronic oven for a predetermined cooking time proper to a selected one of the menus being performed with reference to the reading of the display device. The cooking time adjustment arrangement is intended for facilitating the use of the electronic oven without substantially requiring any experience in handling the oven itself.

The present invention generally relates to an electronic or microwaveoven and, more particularly to a cooking time adjusting arrangement foruse in the electronic oven.

An electronic oven to which the present invention pertains and which isnow in wide use essentially comprises an oven-defining structure havinga hingedly supported door adapted to close an access opening formed atone side of the oven-defining structure, a magnetron for generating highfrequency energy for heat-treating food material within theoven-defining structure, and a timer unit for adjusting the period oftime during which the magnetron is operated so as to apply the highfrequency energy to one particular food material. With the electronicoven, food items can be heat-treated or cooked in an extraordinarilyshort period of time, for example, on the order of seconds, and, in viewof the relatively high speed of cooking, the timer unit plays animportant role in determining the cooking time, i.e., the period of timeduring which the magnetron is operated.

The timer unit heretofore largely employed in the conventionalelectronic oven includes an operating shaft, an operating knob having apointer needle and a calibrated scale imprinted, or otherwise embossed,with a plurality of sequential digits representing the cooking time. Theoperating knob is rigidly mounted on the operating shaft fortransmitting a rotational force of the operating knob to said operatingshaft thereby to operate the timer unit in accordance with the readingof the pointer needle then registered with any one of the digits on thecalibrated scale.

In such a conventional arrrangement, in order to set the timer unit soas to select a proper cooking time with respect to any one particularfood material or item, the user is required to refer to a cooking bookin which the proper cooking time for the particular food material oritem is described, or otherwise to rely on the memory.

In practice, there are a number of food materials and food items thatcan be heat-treated or cooked by the electronic oven and, in view ofthis, relying on memory often results in confusion the, in which caseone particular food material or item cannot be successfully heat-treatedor cooked. The cooking book may be a reliable friend to the user, but itwill be difficult, or inconvenient if not difficult, to find which bookdiscloses a menu the user intends to serve and where such menu isdescribed in the same book.

Some types of conventional electronic ovens are imprinted with aplurality of different menus that can be cooked in different cookingtimes. However, the number of the menus that can be imprinted in thevicinity of the timer unit is limited because of a limited spaceavailable for this purpose.

Accordingly, an essential object of the present invention is to providea cooking time adjusting arrangement for use in the electronic ovenwherein a display device is provided for permitting the user to set thetimer unit with reference to the display device.

Another object of the present invention is to provide a cooking timeadjusting arrangement of the type above referred to, wherein a lightingdevice is further provided for illuminating the display device.

A further object of the present invention is to provide a cooking timeadjusting arrangement of the type above referred to, which can bemanufactured at a relatively low cost into a single unit substantiallyindependent of the body of an electronic oven to which the concept ofthe present invention can be applicable.

A still further object of the present invention is to provide a cookingtime adjusting arrangement of the type above referred to, which can bemounted on any of the commercially available electronic ovens merely byreplacing the front instrument panel with that according to the presentinvention.

A still further object of the present invention is to provide a cookingtime adjusting arrangement of the type above referred to, which enablesa beginner of to readily handle the electronic oven while preventing thenovice from over or undercooking a desired food item.

A still further object of the present invention is to provide a cookingtime adjusting arrangement of the type above referred to, whereincooking by the use of an electronic oven can be performed by merelyrequiring the user to refer to the reading on the display device.

These and other objects and features of the present invention willbecome apparent from the following description taken in conjunction withpreferred embodiments thereof with reference to the accompanyingdrawings, in which;

FIG. 1 is a schematic perspective view showing an electronic oven, witha back covering removed away, according to one preferred embodiment ofthe present invention,

FIG. 2 is a schematic perspective view of a cooking time adjustingarrangement of FIG. 1, shown on an enlarged scale,

FIG. 3 is a front elevational view, on an enlarged scale, of the cookingtime adjusting arrangement of FIG. 2, with a front covering removedaway,

FIG. 4(a) is a schematic perspective view of an essential portion of thearrangement of FIG. 2, showing the details of a drum mounting,

FIG. 4(b) is an exploded view of a portion of FIG. 4(a),

FIG. 5(a) and (b) illustrate a method of connecting the opposite ends ofa cable employed in the arrangement of FIG. 2,

FIG. 6 is a perspective view, on an enlarged scale, of a pointer needleconnected to the cable,

FIG. 7 is a front elevational view of a drive wheel mounted on the timeroperating shaft for moving the cable,

FIG. 8 is a side view of FIG. 7,

FIG. 9(a) is a perspective view of the drive wheel,

FIG. 9(b) is a perspective view, on an enlarged scale, of a half portionof the drive wheel shown in FIG. 9(a), showing the cross-sectionalappearance thereof,

FIG. 10(a) is a front elevational view, on an enlarged scale, of thedrive wheel, showing one surface thereof,

FIG. 10(b) is a top plan view of FIG. 10(a),

FIG. 10(c) is a similar view to FIG. 10(a), showing the opposite surfacethereof,

FIG. 11 is a perspective view of one end of the drum according toanother embodiment of the present invention,

FIG. 12 is a perspective view of the opposite end of the drum accordingto a further embodiment of the present invention,

FIG. 13 is a perspective view of the arrangement incorporating a drumlighting unit according to a still further embodiment of the presentinvention,

FIG. 14(a) is a modification of FIG. 13,

FIG. 14(b) shows a manner of light transmission through the drum in themodification of FIG. 14(a),

FIG. 15(a) is another modification of FIG. 13,

FIG. 15(b) shows a manner of light transmission through the drum inanother modification of FIG. 15(a),

FIG. 16(a) is a further modification of FIG. 13,

FIG. 16(b) shows a manner of light transmission through the drum in thefurther modification of FIG. 16(a),

FIG. 17 is a schematic perspective view of the electronic oven having apocket for accommodating a plurality of menu cards according to a stillfurther embodiment of the present invention,

FIG. 18 is a back plane view, on an enlarged scale, of the pocketshowing the interior thereof,

FIG. 19 is a cross sectional view of an essential portion of FIG. 18,

FIG. 20 is a schematic perspective view of FIG. 18, with the menu cardsremoved away,

FIG. 21 is a front elevational view of a portion of a mounting panel towhich the pocket is attached,

FIG. 22(a) is a schematic perspective view of the electronic oven havingthe display device composed of an interchangeable strip member accordingto a still further embodiment of the present invention,

FIG. 22(b) is a schematic perspective view, on an enlarged scale, of anessential portion of FIG. 22(a) showing a manner of association betweenthe pointer needle and the interchangeable strip member,

FIG. 22(c) is a schematic diagram showing the details of the stripmember,

FIG. 23(a) is a similar view to FIG. 2, showing a still furtherembodiment of the present invention,

FIG. 23(b) is a front elevational view of the embodiment of FIG. 23(a),with the front covering removed away,

FIG. 24 is a schematic perspective view of an essential portion of FIG.23(b), with a portion broken away to show the interior thereof,

FIG. 25 is a schematic perspective view, on an enlarged scale, with aportion broken away to show the application of the lighting unit to theembodiment of FIG. 23(a),

FIG. 26 is a schematic perspective view of a band of film having aprotective covering according to a still further embodiment of thepresent invention,

FIG. 27 is a schematic perspective view, on an enlarged scale, showingan operative connection between the timer operating shaft and a filmwinding mechanism employed in the embodiment of FIG. 23(a),

FIG. 28(a) is a schematic perspective view of a portion of theelectronic oven utilizing an interchangeable strip member having amagnetic member according to a still further embodiment of the presentinvention, and

FIG. 28(b) is a schematic side sectional view showing the fittingposition for the strip member having the magnetic member.

Before the description proceeds, it is to be noted that like parts aredesignated by like reference numerals throughout the accompanyingdrawings for the sake of brevity.

Referring first to FIGS. 1 and 2, the electronic oven to which thepresent invention is applicable comprises an oven-defining structure 1of substantially cubic shape having a hingedly supported door 1a adaptedto close an access opening through which food to be heat-treated isinserted into the oven-defining structure 1. An instrument panel 2 isprovided above the door 1a and suitably supported in position by aframework, for example, a housing structure (not shown) for confiningthe oven-defining structure 1 therein. This instrument panel 2 is formedwith a display window 5 through which a portion of a rotatable drum 3having a plurality of menus imprinted on the peripheral surface thereofand a pointer needle 4 are exposed to the sight of the user and alsowith a substantially vertically extending slot 9 through which a portionof a drum rotating ring 10 for rotating the drum 3 is exposed forpermitting the user to rotate the drum 3 to register one particular menuon the peripheral surface of the drum 3 with the pointer needle 4.

Provided to the right of the display window 5 is a timer operating knob7 mounted on a timer operating shaft 18 (FIG. 3) loosely extendingthrough the instrument panel 2, and a push-button type switch 8 operableso as to, upon closure thereof, initiate radiation of high frequencyenergy at the food within the oven-defining structure 1.

It is to be noted that a timer device 6 is constructed to be driven insynchronism with the radiation of high frequency energy, i.e., closureof the push-button type switch 8, and to interrupt an electric powersupply to the magnetron (not shown) after a predetermined period of timeset by the timer device 6 and has elapsed. .Iadd.

The construction of the generator of high frequency energy, as well asstructure to mount such generator with respect to the oven areconventional, and thus are not shown. Further, the manner of operativelycoupling the timer device 6, the switch 8 and the generator may be anyknown such system, and thus is not shown or described in detail..Iaddend.

The pointer needle 4, during the operation of the timer device 6, movesfrom one position corresponding to the cooking time proper to oneparticular food in the oven-defining structure 1 to another position,i.e., OFF position, thereby visually representing the elapse of thecooking time. For this purpose, the pointer needle 4 is operativelycoupled with the timer operating shaft 18 in a manner as will bedescribed later. In any event, in the above arrangement, if the userdesires to set the timer device 6 so as to operate the electronic ovenfor a certain period of time required for cooking or heat-treating oneparticular food item within the oven-defining structure 1, the usermerely turns the timer operating knob 7 to such a position that themovable pointer needle 4 is aligned with a marking indicative of thatcertain period of time which is imprinted, or otherwise embossed, on theperipheral surface of the drum 3 while viewing it through the displaywindow 5. Subsequently, the switch 8 is depressed to supply the electricpower to the magnetron. The timer device 6 is driven during thispredetermined period of time and, upon the lapse of the predeterminedperiod of time, it halts operation with the pointer needle 4 returned tothe OFF position.

Referring now to FIGS. 3 and 4(a) and (b), the rotary drum 3 has a pairof opposed ends integrally formed with axial projections 12 and 14 inalignment with the longitudinal axis of said drum 3, respectively.Mounted on these axial projections 12 and 14 and rigidly secured to thedrum 3 is the drum operating ring 10 and another ring 11 of smallerdiameter than that of the ring 10.

The drum 3 is rotatably supported in position by a chassis 21 through apair of bearing blocks 13a and 13b rigidly secured to said chassis 21and respectively receiving therein the axial projections 12 and 14 ofthe drum 3. As shown in FIGS. 4(a) and (b), the drum 3 is normallybiased in one direction towards the bearing block 13a by a compressionspring 15 which is mounted on the axial projection 14 and interposedbetween said ring 11 and said bearing block 13b, thereby to impart asufficient friction to the rotation of the drum 3. A washer 16 ofsufficient size is provided between the bearing block 13b and thecompression spring 15 for facilitating a smooth rotation of the drum 3,thereby to avoid a possibility that the corresponding end extremity ofthe compression spring 15 may be caught by a portion of the bearingblock 13b.

In the instance shown in FIG. 3, the drum 3 is imprinted on itsperipheral surface with a time scale under the heading of TIME inaddition to various markings indicative of, for example, menus and thenumber of a particular food item under the same menu while, in theinstance shown in FIG. 4(a), a separate time scale 17 is used andhorizontally suspended from the chassis 21.

Referring still to FIG. 3, the timer operating shaft 18 has a drivewheel 19 non-rotatably mounted thereon in a manner as will be describedlater, rotation of the timer operating shaft 18 being transmitted to thepointer needle 4 through said drive wheel 19 by means of a cable 20. Aplurality of idle pulleys 22, 23, 24, 25 and 26 are rotatably supportedby the chassis 21 for guiding the cable 20. As clearly shown in FIG. 3,the cable 20 has a pair of opposed ends connected with each other by atension spring 27 and suspended around the pulleys and the drive wheelin the order of 25, 24, 23, 22, 19 and 26.

In the above arrangement, as the operating knob 7 is turned or duringthe operation of the timer device 6, the cable 20 runs with the tensionspring 27 moving between two positions respectively locating adjacent tothe ends of the rotary drum 3.

The chassis 21 is formed as at 28 and 29 with a pair of downwardprojections each terminating at a position adjacent to the linear pathof travel of the tension spring 27. These downward projections 28 and 29are provided for facilitating a procedure of suspending the cable 20around the pulleys 22 to 26 via the drive wheel 19, which will behereinafter described with reference to FIGS. 5(a) and (b).

As shown in FIGS. 5(a) and (b), the cable 20 has each end tied toprovide a loop 30 and 31 of a size sufficient enough to permit thecorresponding projection 28 and 29 to extend therethrough as shown inFIG. 5(a) during the cable suspending procedure. The space between theseprojections 28 and 29 is greater than the length of the tension spring27 without being loaded and substantially equal to the length of thetension spring 27 loaded so as to exert on the cable 20 a sufficienttension to ensure a stable movement of the pointer needle 4 connectedwith the cable 20 in a manner as will be described later.

Operation of these downward projections 28 and 29 are as follows. First,one loop 30 must be formed at the corresponding end of the cable 20 andthen engaged with the projection 28. After the cable 20 has been passedthrough the pulleys 25, 24, 23 and 22, then the drive wheel 19 andfinally the pulley 26, in the order given above, the other loop 31should be formed at the corresponding end of the cable 20 and thenengaged with the other projection 29 without permitting the cable 20 tobe loosened. While the loops 30 and 31 of the cable 20 are respectivelyengaged with the projections 28 and 29 of the chassis 21, one end of thetension spring 27 should be connected with either of these loops 30 or31 and the other end of the tension spring should be subsequentlyconnected with the other loop 31 or 30 while a single attendant workerengaged in the assemblage of the electronic oven pulls the tensionspring 27. This condition is illustrated in FIG. 5(a).

What is required to do thereafter is to disengage the loops 30 and 31from the corresponding projections 28 and 29, as shown in FIG. 5(b).

From the foregoing, it is clear that the provision of the projections 28and 29 in the chassis is advantageous in that only the single attendantworker can perform the cable suspending procedure.

FIG. 6 illustrates a manner of connection of the movable pointer needle4 to the cable 20. The chassis 21 is mounted with a guide rail 34 ofsubstantially channel-shaped cross section, which extends horizontallybetween the pulleys 23 and 24. This guide rail 34 carries thereon ablock 32 slidable along said guide rail 34 and to which the pointerneedle 4 is secured. The block 32 is rigidly mounted with a fittingplate 33 which is in turn connected with the cable 20 as clearly shownin FIG. 6, in such a manner that the block 32 can be pressed towards theguide rail 34 by the tension exerted by the cable 20 thereby to ensure astable movement of the pointer needle 4. Preferably, the size of thefitting plate 33 is greater than that of the block 32 so that thepressing force transmitted from the cable 20 to the block 32 can beuniformly distributed to said block 32 to ensure a more stable movementof the pointer needle 4 without causing the latter to incline during themovement.

FIGS. 7 to 10 illustrate the details of the drive wheel 19 and a mannerof connection of the cable 20 to said drive wheel 19. Referring first toFIG. 7, the drive wheel 19 mounted on the timer operating shaft 18 is sopositioned that a portion of the cable 20 between the pulleys 22 and 26after having passed round the drive wheel 19 extends in alignment withthe tangential direction of the drive wheel 19. This arrangement isadvantageous in that no substantial force derived from the tensionimposed on the cable 20 by means of the tension spring 27 is transmittedthrough the drive wheel 19 to the timer operating shaft 18, which mayotherwise act on the shaft 18 in the direction perpendicular to thelongitudinal axis of said shaft 18 if such force were applied to thedrive wheel 19. Consequently, it is clear that the timer operating shaft18 can be smoothly rotated, without requiring an excessive force torotate the knob 7 and without reducing the life of the timer device 6.

As shown in FIG. 8, the pulleys 22 and 26 respectively positionedsubstantially above and below the drive wheel 19 are displaced in theopposite directions from the plane of the drive wheel 19. This isachieved by displacing the planes of flanges 21a and 21b formedintegrally with the chassis 21 and to which the pulleys 22 and 26 arerotatably fitted. While the pulleys 22 and 26 are displaced from theplane of the drive wheel 19 as hereinbefore described, the width of aguide groove formed along the periphery of said drive wheel 19 aroundwhich the cable 20 is wound is greater than the difference between thelevel of the plane of the flange 21a and that of the flange 21b. This isfor the purpose of avoiding a cross-over of portions of the cable 20which extend in alignment with the tangential direction of the drivewheel 19. This cross-over of the cable 20 should be avoided in view ofthe fact that, if it were permitted to occur, the section of the cable20 where the cross-over occurs will be worn out. The width of theperipheral groove on the drive wheel 19 should be determined dependingupon the number of winding of the cable 20 around said wheel 19 in sucha way that windings of the cable 20 around the wheel 19 do not overlapwith respect to each other within the peripheral guide groove.

Referring now to FIGS. 9 and 10, in which the details of the drive wheel19 are shown, it should be understood that the drive wheel 19 must befirmly mounted on the timer operating shaft 18 partly because, once ithas been mounted on said shaft 18, there is no possibility of removingit from the shaft 18 and partly because, even if the drive wheel 19 isarbitrarily rotated in response to the rotation of the timer operatingshaft 18, a notch 35 formed thereon should return to a predeterminedposition upon completion of the operation of the timer device 6. To thisend, while the shaft 18 is provided with a pin 36 (FIG. 10(c)) extendingtherethrough at right angles to the longitudinal axis of said shaft 18,the drive wheel 19 is provided, on the surface facing towards the timerdevice 6, with a substantially rectangular hollow projection 37 havingthe interior wall formed with two pairs of protuberances 38 and 39 onboth sides of the central hole of the drive wheel 19 through which theshaft 18 extends, each pair of protuberances facing towards each other.It is to be noted that the space between each pair of protuberances 38and 39 is smaller than the diameter of the pin 36 whereby, when thedrive wheel 19 is mounted on the shaft 18, the protuberances 38 and 39are partially smashed to permit the pin 36 to be firmly sandwichedbetween the protuberances within the rectangular hollow projection 37.

Considering the mass-production of the electronic oven according to thepresent invention, there will be a possibility that the pin 36 isinserted through the shaft 18 with the longitudinal axis thereofdisplaced from the longitudinal axis of the operating shaft 18. In suchcase, the protuberances 38 and 39 located on the side in which the pin36 has become displaced, may be partially scraped by a knife of the liketo permit the pin 36 to be held in position within the projection 37.

The drive wheel 19 is formed on the other surface with a boss 40 throughwhich the operating shaft 18 extends and also with a hook portion 41adjacent to the periphery of said wheel 19 to which that portion of thecable 20 wound around said wheel 19 is engaged as shown in FIG. 7. Thedrive wheel 19 is also formed with the notch 35 substantially opposed tothe hook portion 41 and a pair of projections 42 on both sides of saidnotch 35 which are projecting towards the instrument panel 2 from theplane of the wheel 19. These projections 42 are integrally formed withthe drive wheel 19 by means of a plastic molding method duringmanufacture thereof and are provided for the purpose of permitting theattendant worker to successfully wind the cable 20 around the wheel 19without causing the cable to be displaced from said wheel 19 in such amanner as indicated by the dotted lines in FIG. 10(b). To this end, thespace m₁ between these projections 42 is made smaller than the spaceindicated by m₂ in FIG. 10(b).

From the foregoing description in connection with the first preferredembodiment of the present invention, it has now become clear thatrotation of the timer operating knob 7 and, thus, the timer operatingshaft 18 can be transmitted to the pointer needle 4 so as to slide thelatter along the guide rail 34 whereby, by aligning the pointer needle 4with any one of the markings on the peripheral surface of the drum 3,the required cooking time can be automatically set on the timer device6. It is also clear that, upon completion of the operation of the timerdevice 6, i.e., after the lapse of the required cooking time, thepointer needle 4 can return to the initial or OFF position in readinessfor the subsequent operation of the electronic oven.

Another embodiment shown in FIG. 11 is similar to the foregoingembodiment. However, rotation of the timer operating shaft 18 is,according to the embodiment of FIG. 11 transmitted not only to themovable pointer needle 4, but also to the drum 3 which has beendescribed as manually rotatable in the foregoing embodiment.

To this end, the projection 12 of the drum 3, in this embodiment of FIG.11, extends through the bearing block 13a and is mounted rigidly with apulley 44 around which a portion of the cable 20 between the pulleys 24and 25 is wound so that the movement of the cable 20 causes the drum 3to rotate. This arrangement should be designed such that a substantially360° rotation of the drum 3 occurs upon rotation of the operating shaft18 from the OFF position to another position indicative of the maximumcooking time that can be set to the timer device 6. Furthermore, themarkings indicative of menus which can be cooked in different times arepreferably imprinted on the peripheral surface of the drum 3 so as tohelically position thereon as shown in FIG. 11.

A system similar to the embodiment of FIG. 11 may be practiced in amanner as shown in FIG. 12, wherein the various pulleys, the drivewheel, the pointer needle, the cable and their associated parts thathave been described as employed in the foregoing embodiments areeliminated. Instead, according to the embodiment shown in FIG. 12, abevel gear system is employed. This bevel gear system comprises a firstbevel gear 45 rigidly mounted on the operating shaft 18 and a secondbevel gear 46 rigidly mounted on the projection 14 of the drum. 3Projection 14 is made to extends through the bearing block 13b, wherebyrotation of the operating shaft 18 can be transmitted to the drum 3through said first gear 45 via said second gear 46 in constant mesh withsaid first gear 45, thereby causing the drum 3 to rotate about thelongitudinal axis thereof.

In the embodiment of FIG. 12, the time scale 17 that has been describedas employed in the foregoing embodiments is also omitted and, insteadthereof, an index mark 47 is preferably integrally formed with theinstrument panel 2 so as to project into the window 5 as clearly shown.

Each of the foregoing embodiments shown in FIG. 11 and FIG. 12 has anadvantage in that the cooking time required in cooking one particularfood item can be set to the timer device 6 merely by rotating the timeroperating shaft 18 until the pointer needle 4 in the embodiment of FIG.11 or the index mark 47 in the embodiment of FIG. 12 is aligned with oneof the markings which indicate the desired food item to be cooked.

FIGS. 13 to 16 show various types of a lighting device which areapplicable with any of the foregoing embodiments of the presentinvention for illuminating the rotary drum 3. The provision of thislighting device is advantageous since this ensures that, at most, a verysmall portion of the peripheral surface of the drum 3, on which thevarious menus and the number and/or quantity of each of said menus areimprinted or otherwise embossed and which is exposed to the sight of theuser through the window 5, will be shaded, which may in fact occurwithout the lighting device.

Referring first to FIG. 13, the drum 3 employed in this instance ispreferably made of a light transmissive material, i.e., material of anature which permits passage of light therethrough, and an elongated,substantially cylindrical lamp 48 is housed within said drum 3 inalignment with the longitudinal axis of said drum 3. For supplyingelectrical power from a suitable power source (not shown), the lamp 48is inserted in a socket 49, which may be integrally formed with thebearing block 13b and concurrently serves as an axis about which saiddrum 3 rotates. A pair of lead wires 51 are extended through saidbearing block 13b and connected to the lamp 48 through the socket 49.Rotation of the drum 3 incident to a turning of the operating ring 10does not cause the lead wires 51 to twist about the axis of rotation ofthe drum 3.

In FIGS. 14(a) and (b), the drum 3 is similarly made of a lighttransmissive material and an electrical lamp 52 is positioned adjacentto the peripheral rim of that end of the drum 3 adjacent to the bearingblock 13b so as to illuminate the drum 3. In this case, it is preferableto apply a coating of a white paint 54 on the inner peripheral surfaceof said drum while figures or characters representing the various menusand the number and/or quantity thereof are perforated on a film 53 ofopaque material which is in turn applied to the outer peripheral surfaceof said drum 3. In this arrangement, rays of light emitted from theelectrical lamp 52 travel as shown in FIG. 14(b) with portions of saidlight rays leaking through the perforated figure or characters on thefilm 53, thereby permitting the figure or characters to be illuminated.

In the case where the rotary drum 3 is made of opaque material and it isdesired not to mount the lamp within the drum 3 as is the case of FIG.13, the following arrangements shown in FIGS. 15 and 16 are possible.

In the arrangement of FIG. 15, a plurality of electrical lamps 55 areprovided substantially above the rotary drum 3 so as to illuminate theportion of the peripheral surface of the drum 3 exposed to the outsidethrough the window 5. These lamps 55 are shielded from view by aremovable covering 56 forming a part of the front instrument panel 2.Preferably, this covering 56 is fitted to the chassis 21 by means of aplurality of screws threaded thereto at 57 and can be removed, if thesescrews 57 are undone, for replacement of are exhausted lamp with a newone.

In the arrangement of FIG. 16, the rotary drum 3 is substantiallyencircled by a covering 59 having an opening 59a, said covering 59 beingsupported by the chassis 21 with said opening 59a in alignment with thewindow 5. A lamp 58 is secured to said covering 59 at the back of thedrum 3 with respect to the opening 59a or the window 5 as clearly shownin FIG. 16(b). The interior surface of said covering 59 serves as areflector so that rays of light emitted from the lamp 58 travel,reflected by said interior surface of said covering 59, to the portionof the drum 3 facing towards the window 5 thereby to illuminate thatportion of said drum 3.

Instead of the use of the drum having the peripheral surface imprintedwith the various menus and the number and/or quantity of each of themenus, which has been described as employed in the foregoingembodiments, employment of a plurality of cooking cards which can beselectively drawn from a casing attached to the front instrument panel 2is possible. This will be hereinafter described with reference to FIG.17 to FIG. 19.

Referring now to these drawings, the front instrument panel 2 above thedoor is detachably provided with a housing 62 for accommodating thereina plurality of cooking cards 60 and at least one casing 61 of a similarsize to each of said cards 60 pivotally supported within said housing 62in such a manner as will be described later. Each of these cooking cards60 is imprinted on one surface with a plurality of menus and the cookingtimes respectively corresponding to the menus whereby the user can setthe timer device 6 through the timer operating knob 7 while referring toa selected one of said cooking cards 60. The casing 61 is used toaccommodate therein a sheet of paper or the like on which the userwrites additional menus and the associated cooking times therefor whichare not described on any one of the cooking cards 60.

Each of these cards 60 and the casing 61 is of a substantiallyrectangular shape and is manually pivotable between a locked positionwherein it is housed within the housing 62 and concealed from view andanother upright position wherein it stands upright and is exposed to thesight of the user. For enabling the user to move each of these cards andthe casing, respectively integrally formed with index knobs 60a and 61a,which are always exposed to the sight of the user even though the card60 or the casing 61 is in the locked position.

FIG. 18 illustrates the interior of the housing 62 after it has beenremoved from the instrument panel 2. As shown in FIG. 18, the housing 62is integrally formed with a substantially cylindrical projection 63 onwhich the cards 60 and the casing 61 are rotatably mounted. It is to benoted that the position of the cylindrical projection 63 with respect tothe housing 62 and the hole formed in each of the cards 60 and thecasing 61 for permitting the projection 63 to pass therethrough are tobe selected such that a maximum of the surface area of each of the cards60 or the casing 61 in the upright position can be exposed to theoutside of the housing 62. For this purpose, as viewed from FIG. 18, theprojection 63 is located at a position adjacent to the upper rightcorner of the configuration of the housing 62.

Referring still to FIG. 18, the casing 61 is shown as conditioned in theupright position and apparently tends to pivot to the locked position byits own gravity. It is clearly undesirable if the casing 61, once movedto the upright position, moves back to the locked position by its owngravity. To avoid this, a leaf spring 65 is provided. This leaf spring65 has one end portion held in position within the housing 62 by meansof a plurality of posts 67 and the other end portion bent to provide afeeler 65a collapsibly engageable in a recess 64 formed in each of thecards 60 and the casing 61. Positioned above the feeler 65a of the leafspring 65 is a stopper 66 integrally formed with the housing 62 forpreventing each of the cards 60 and the casing 61 from being excessivelyrotated beyond the upright position.

In the above arrangement, if one desires to raise one of the cards 60and the casing 61 from the locked position to the upright positioncausing it to rotate about the projection 63, the feeler 65a of the leafspring 65 relatively slides along the corner edge of said card 60 orcasing 61, biased thereto by its own resiliency, and finally clicks intothe recess 64, formed in each of the cards 60 and the casing 61, wherebythe card 60 or casing 61 thus raised to the upright position can be heldin said upright position with the stopper 66 restricting the furtherrotation thereof beyond said upright position.

As will be described later, the housing 62 with cards 60 and casing 61therein is detachably fitted to the instrument panel 2 for permittingthe user to clean, as desired, the housing 62, the cards 60 and thecasing 61. So far as the arrangement is such as hereinbefore described,there will be a difficulty in re-mounting the housing 62 with cards 60and casing 61 therein to the instrument panel 2 once they have beenremoved from said panel 2. For avoiding this, the leaf spring 65 issubstantially bogged or hogged at the center, as shown by the dottedline in FIG. 18, of the end portion thereof accommodated in between eachof the posts 67 and a corresponding side flange of the housing 62whereby said leaf spring 65 is firmly held in position within saidhousing 62 and is not removed therefrom.

Hereinafter, a method of reliably and effectively mounting the cards 60and the casing 61 to the cylindrical projection 63 of the housing 62will be described with reference to FIGS. 18 and 19. When the housing 62is to be mounted to the instrument panel 2, the cards 60 and casing 61are first mounted on the cylindrical projection 63. In view of this,when the housing 62 with cards 60 and casing 61 therein is to be mountedto the instrument panel 2, there will be a possibility that some of thecards 60 and/or the casing 61 become disengaged from the cylindricalprojection 63. To avoid this, while the outer diameter of thecylindrical projection 63 is made slightly smaller than the diameter ofthe hole formed in each of the cards 60 and the casing 61, thecylindrical projection 63 is integrally formed with one or more, forexample, four, projections 68, 69, 70 and 71 circumferentiallyequidistantly spaced with respect to each other and protruding in thedirection at right angles to the longitudinal axis of said projection63. In addition, the length of the cylindrical projection 63 is madeslightly greater than the sum of thicknesses of the cards 60 and thecasing 61. In this arrangement, although a relatively great pushingforce is required in mounting each card 60 and casing 61 on thecylindrical projection 63 of the housing 62, none of the cards 60 andcasing 61 will become detached therefrom once they have been thusmounted because of the projections 68 to 71. In addition, even when thehousing 62 with cards 60 and casing 61 therein is removed from theinstrument panel 2 for cleaning, no cards 60 and casing 61 willarbitrarily disengage from the cylindrical projection 63 of the housing.

A method of mounting the housing 62 with cards 60 and casing 61 thereinto the instrument panel 2 will be hereinafter fully described withreference to FIGS. 19 to 21. As shown, the housing 62 is integrallyformed with a plurality of engagements such as indicated by 72, 74, 76,80 for engagement into corresponding openings 73, 75, 77 and 81 formedin the instrument panel 2. One of the engagements, such as indicated by76 is arrow-headed while the cylindrical projection 63 is integrallyformed with an arrow-headed engagement 78, both the arrow-headedengagements 76 and 78 serving as hooks and each having a sufficientresiliency as to permit the housing 62 with cards 60 and casing 61 tobe, when mounted to the instrument panel 2, firmly carried by said panel2 in a predetermined position in a manner clearly shown in FIG. 19. Inother words, when the housing 62 with cards 60 and casing 61 therein isto be mounted to the instrument panel 2, the engagements 72, 74 and 80are first engaged into the corresponding openings 73, 75 and 81 in theinstrument panel 2 and, then, an external pushing force is applied tothe housing 62 to allow the arrow-headed engagement 76 and 78 to beelastically inserted into the corresponding openings 77 and 79 untilsaid arrow-headed engagements 76 and 78 engage the peripheral edges ofthe openings 77 and 79, respectively. FIG. 19 clearly illustrates thecondition in which the arrow-headed engagement 78 is held in positionwithin the openings 79.

It is to be noted that, since the cylindrical projection 63 has a lengthslightly greater than the sum of thicknesses of the cards 60 and casing61, a portion of the instrument panel 2 around the opening 79 isrecessed to provide a space 79a for accommodating therein the lateralprojections 68 to 71 on the free end of the cylindrical projections 63.Nevertheless, the depth of the interior of the housing 62 in which thecards 60 and the casing 61 are accommodated in the manner ashereinbefore described is determined depending upon the sum of thethicknesses of the cards 60 and casing 61 and should be selected such asto permit each of said cards 60 and casing 61 to be steadily moved fromthe locked position to the upright position about the substantiallycylindrical projection 63 while backed up by the instrument panel 2 andthe housing 62 from both sides thereof.

Preferably, the cylindrical projection 63 is formed with a cut-outportion as shown at 63a adjacent to the root of the arrow-headedengagement 78. This is particularly advantageous in that, in the casewhere the diameter of the hole in any one of the cards 60 and casing 61is slightly smaller or greater than the outer diameter of the projection63, the cut-out portion 63a provides a clearance whereby such cardand/or casing can be effectively mounted within the housing 62 with theprojection 63 extending through said hole. In addition thereto, thehousing 62 including the various parts integrally formed with saidhousing 62 is preferably made of synthetic resin in a similar way asemployed in manufacture of the instrument panel 2.

Removal of the housing 62 with cards 60 and casing 61 therein is notalways effected only when cleaning is to be performed. For example, thesame may be effected when some of the cards 60 and/or the casing 61 areto be replaced by other cards.

What is illustrated in FIGS. 22(a) to (b) is an arrangement wherein therotary drum 3, that has been described as employed in the firstpreferred embodiment of the present invention with reference to FIGS. 3to 10, is replaced with a plurality of interchangeable cooking scales82.

As clearly shown in FIG. 22(c), each of these cooking scales 82 is inthe form of a substantially rectangular strip, preferably made ofsynthetic resin, and has the front face imprinted with a plurality ofmenus and the cooking times required in cooking the respective menus. Asimilar imprinting may be made on the back face of said scale 82. Thecooking times imprinted on the cooking scale 82 provides, in the sameway as in the foregoing embodiment shown in either FIGS. 3 to 10 or FIG.11, the positions for movement of the pointer needle 4, to whichreference is made by the user in setting the timer device 6.

For interchangeably accommodating a selected one of the cooking scales82 in position with respect to the window 5, the instrument panel 2 ofthe electronic oven positioned above the hingedly supported door 1a isdouble-walled at a portion corresponding to the window 5, therebyproviding an inlet 2a and a space 2b into which each of said scales 82is selectively inserted, said inlet 2a being located at a positionremote from and opposed to that portion of the instrument panel 2through which the timer operating shaft 18 extends.

Instead of providing the cooking times on each of the interchangeablecooking scales 82, the time scale shown in FIGS. 4(a), 6, 11, 13, 14(a)and 15(b), which is commonly designated by 17, may be neverthelessemployed in the embodiment of FIGS. 22(a) to (c).

The embodiment of FIGS. 22(a) to (c) is advantageous in that, while theperipheral surface of the drum 3 in the foregoing embodiments isnaturally limited by the diameter of said drum 3, the menus with orwithout corresponding cooking times can be displayed in a greater numberthan that can be imprinted, or otherwise embossed, on the drum 3,depending upon the number of the interchangeable cooking scales 82.

The embodiment shown in FIG. 23 to FIG. 27 employs a belt of syntheticfilm having one surface, exposed to the sight of the user, imprintedwith the various menus and the number and/or quantity of each of thesemenus, which is an alternative of either the drum or the cooking scale.Before the description of this embodiment proceeds, it is to be notedthat a system for moving the pointer needle 4 may be substantially thesame as employed in the foregoing embodiment of FIGS. 3 to 10 and,therefore, the details thereof are herein omitted for the sake ofbrevity.

Referring first to FIGS. 23(a) and (b), the instrument panel 2 isprovided with a circular opening 9a (FIG. 27) instead of the employmentof the rectangular opening 9 in the foregoing embodiments wherein thedrum 3 is employed. Extending through said circular opening 9a is ashaft 84 having one end exposed outside the instrument panel 2 andmounted with an operating knob 83 and the other end rigidly mounted witha bevel gear 85, said shaft 84 being rotatably supported at asubstantially intermediate portion by the chassis 21 by means of abracket 94 rigidly secured to said chassis 21. A pair of elongated rolls89 positioned roll 90. The rolls have formed on both ends thereof toeach other, each of which is formed on both ends thereof correspondingshaft members which are in turn journalled to bearing members 95 and 96,respectively. The members 95 and 96 are, in turn, secured to the chassis21 by means of a plurality of screws such as indicated by 97. Each ofthese rolls 89 and 90 is biased towards the bearing member 95 by acompression spring 108 disposed on the corresponding shaft member of theroll between that end thereof and the bearing member 96 and functioningin the same way as the compression spring 15 shown in FIGS. 4(a) and(b).

These rolls 89 and 90 are rotatable in the same direction in synchronismwith respect to each other in response to rotation of the operating knob83. For this purpose, a gear 87 on a connecting rod which has one endrigidly mounted with said gear 87 and the other end with a bevel gear 86in constant mesh with the bevel gear 85, a substantially intermediateportion of said connecting rod being rotatably supported by the bearingmember 95, is meshed on both sides thereof with a pair of driven gears91 and 92 rigidly mounted respectively on the corresponding shaftmembers of the rolls 89 and 90 between that ends of said rolls 89 and 90and said bearing member 95.

Suspended between said rolls 89 and 90 is the belt 88 of synthetic filmhaving one end connected with either the roll 89 or the roll 90 and theother connected with the other roll 90 or 89 and having a length greaterthan the distance between said two rolls 89 and 90. This belt 88 has onesurface exposed towards the window 5 and imprinted on said surface withthe various menus and the number and/or quantity of each of said menusas clearly shown in FIG. 23(b).

From the foregoing arrangement, it is clear that rotation of theoperating knob 83 is transmitted to the rolls 89 and 90, thus causingthe latter to rotate in the same direction in synchronism with eachother with either of these rolls 89 and 90 acting to wind up the belt 88while the other roll acting to release the belt. As a result of this,the different menus and the number and/or quantity thereof imprinted onthe surface of said belt 88 are successively shifted between said rolls89 and 90 from above or bottom depending upon the direction of rotationof the operating knob 83.

For avoiding a possible fluttering of a portion of the belt 88 locatedbetween said rolls 89 and 90, a back-up plate 98 is suspended betweenthe bearing members 95 and 96 which extends behind said belt 88. Thisback-up plate 98 is preferably made of transparent or semi-transparentsynthetic material for the reason as will be described.

As is well known to those skilled in the art, most electronic ovens nowcommercially available are provided with an electrical lamp forilluminating the interior of the oven-defining structure. The electricallamp is, as indicated by 100 in FIG. 25, usually positioned above theceiling panel forming a part of the oven-defining structure. In theembodiment of FIGS. 23 to 27, this electrical lamp 100 may be employedfor concurrently illuminating the belt 88 of synthetic film as clearlyshown in FIG. 25.

For the above purpose, the chassis 21 should be, as at 21d, opened topermit rays of light from said lamp 100 to travel towards the belt 88through the back-up plate 98. In this case, no extra electrical lampother than the lamp 100 initially intended to illuminate the interior ofthe oven-defining structure is required.

There will be a possibility that the belt 88 becomes dirty during theservice of the electronic oven in a kitchen where the humidity isrelatively high, in which case the menus and other informations on thesurface of the belt 88 cannot be clearly represented. To avoid this, apair of cleaning members 101, each made of felt cloth or brush, areprovided; one being rigidly carried by the time scale 17 and facingtowards the belt 88 and the other being rigidly carried by the back-upplate 98 and facing towards said belt 88 as clearly shown in FIG. 24.The two cleaning members 101 sandwich said belt 88 in cooperation witheach other whereby, each time said belt 88 is moved between the rolls 89and 90, both surfaces of said film can be swept.

However, there is also a possibility that, during frequent sweeping thebelt surfaces by means of the cleaning members 101, some or all of themenus and the other informations imprinted on the surface of said belt88 are erased therefrom. To avoid this disadvantage, it is preferably toprovide a protective film 103 applied on the relevant surface of thebelt 88 by the use of a suitable known adhesive material therebypreventing the cleaing member 101 from contacting the surface of thebelt 88 on which the menus and the other informations are imprinted.

In the case where the belt 88 of synthetic film is divided into, forexample, three portions respectively carrying thereon types, the numberand/or quantity of the menus to be re-heated, cooked and defrosted bythe electronic oven, rotation of the operating knob 83 is preferablylimited to a substantial angle of 360°. For this purpose, the shaft 84is provided with a pin 105 extending at right angles to the longitudinalaxis of said shaft 84 said pin 105 cooperating with a stopper 106, whichis integrally formed with the bracket 94. This shaft 84 is also providedwith a pin 104 for rigid connection with the operating knob 83 mountedon said shaft 84. Disposed on the instrument panel 2 around the opening9a through which the shaft 84 extends is an indication of the purposesof use of the electronic oven which corresponds to the three portions ofthe belt 88.

In the above arrangement, it is clear that the rotation of the operatingknob 83 and, thus, the shaft 84 is limited to the angle of approximately360°. As shown in FIG. 23(b), the operating knob 83 is preferablyprovided thereon with an index marking 83a for visually indicating tothe user what portion of the belt 88 is aligned with the window 5.

It is to be noted that the belt 88 may be employed in the form of anendless belt.

The embodiment of FIGS. 28(a) and (b) illustrates that a plurality ofcooking scales 109, each having one surface imprinted with the variousmenus and the corresponding number and/or quantity with or without therespective cooking times, are selectively attached to the instrumentpanel 2 by the effect of magnetic attraction.

Referring to these drawings, this embodiment employs the same system ofmoving the pointer needle 4 in response to rotation of the timeroperating knob 7. However, the instrument is provided with a magneticmember 110, either in the form of a magnetic strip or in the form of aplurality of magnetic pieces, arranged below the plane of movement ofthe pointer needle 4. For attaching each of the cooking scales 109 tosaid magnetic member 110 on the instrument panel 2, each cooking scale109 may be made of metallic material, or otherwise may be plated on theopposite surface with a metallic member, either in the form of ametallic strip or in the form of a plurality of metallic piecescorresponding to the magnetic pieces if employed. Alternatively, in thecase where the instrument panel 2 is made of metallic material, eachcooking scale 109 has the opposite surface plated with the magneticmember.

In the foregoing embodiment of FIGS. 23(a) and (b), each cooking scale109 is associated with the pointer needle 4 in a similar manner as inthe embodiment of FIGS. 22(a) to (c). However, if each of theinterchangeable cooking scales 109 is provided on the opposite surfacewith the magnetic member, it can be used in any type of conventionalelectronic oven if the latter has at least one metallic portion withinthe sight of the user.

Of course, the greater the number of the interchangeable cooking scales109, the greater the menus and the number and/or quantity of each ofsaid menus can be imprinted thereon. The embodiment of FIGS. 28(a) and(b) is an example in which the cooking time adjusting device accordingto the present invention can be manufactured at lower cost than requiredin any of the foregoing embodiment.

From the foregoing full description of the present invention, it has nowbecome clear that the cooking time adjusting device enables the user tofeel comfortable about handling the electronic oven. Furthermore, itpermits a beginner of cooking to readily operate or use the electronicoven without substantially requiring any experience in handling theoven.

Although the present invention has been fully described, it is to benoted that various changes and modifications are apparent to thoseskilled in the art. Therefore, unless otherwise they depart from thetrue scope of the present invention, they should be construed asincluded within said scope of the present invention.

What is claimed is:
 1. A cooking time adjusting arrangement for use inan electronic oven, said arrangement being utilized in an electronicoven including an oven-defining structure having an access opening,means positioned for generating high frequency energy toward theinterior of said oven-defining structure and a hingedly supported doorfor .[.selectively.]. covering the access opening of said oven-definingstructure, said adjusting arrangement comprising:a timer device havingan operating shaft for setting the timer to any desired operatingperiod, said means for generating high frequency energy beingoperatively coupled to said timer device and operating during saidoperation period; an instrument panel having a front and back andpositioned on said oven-defining structure and having a window portionand an aperture therein, said timer device being positioned adjacent theback of said panel and said operating shaft of said timer extendingthrough said aperture; a movable pointer needle, operatively coupled tosaid operating shaft and positioned to move along said window portionfor indicating the operating time of said means for generating highfrequency energy; and display means positioned behind said windowportion for visually representing various information relating to menus,corresponding cooking times and operating time, said display meanscomprised of a rotatable drum, the peripheral surface thereof havingsaid information thereon. .[.2. A cooking time adjusting arrangement asclaimed in claim 1, wherein said display means comprises a plurality ofinterchangeable strip members each having at least one surface carryingsaid informations, said strip members being capable of being selectivelymounted to said instrument panel so as to display said informations oneach of said strip members through said window portion..]. .[.3. Acooking time adjusting arrangement as claimed in claim 2, wherein saidstrip members are selectively insertable in said instrument panel so asto display said information on each of said strip members through saidwindow portion..]. .[.4. A cooking time adjusting arrangement as claimedin claim 2, wherein each of said strip members is capable of beingselectively fitted to said instrument panel by the effect of magneticattraction..]. .[.5. A cooking time adjusting arrangement as claimed inclaim 1, wherein said display means comprises a pair of synchronouslyrotatably supported rolls spaced one above the other in equidistantlyspaced relation with respect to each other, means for rotating saidrolls in the same direction in synchronism with respect to each other, abelt wound around each of said rolls and having one front surfacecarrying said informations, said belt being shiftable upon rotation ofany one of said rolls..]. .[.6. A cooking time adjusting arrangement asclaimed in claim 5, further comprising a cleaning device for sweepingsaid belt to keep the latter clear..]. .[.7. A cooking time adjustingarrangement as claimed in claim 5, wherein said belt has said frontsurface applied with a protective film..]. .[.8. A cooking timeadjusting arrangement as claimed in claim 5, wherein said belt is madeof transparent synthetic material and further comprising an electricallight positioned backwards of said belt and above the ceiling of saidoven-defining structure for illuminating said belt and the interior ofsaid oven-defining structure..]..Iadd.
 9. A cooking time adjustingarrangement as claimed in claim 1, wherein said rotatable drum is biasedin one direction by a compression spring mounted on a shaft of saiddrum. .Iaddend..Iadd.
 10. A cooking time adjusting arrangement asclaimed in claim 1, wherein said drum is made of transparent materialand further comprising an electrical lamp for illuminating said drum,said lamp being housed within said drum. .Iaddend..Iadd.
 11. A cookingtime adjusting arrangement as claimed in claim 10, wherein said drum isrotatably supported by a socket for supplying a power therethrough tosaid lamp. .Iaddend. .Iadd.
 12. A cooking time adjusting arrangement asclaimed in claim 10, wherein said lamp is operatively positioned toproject rays of light to the peripheral rim of said drum..Iaddend..Iadd.
 13. A cooking time adjusting arrangement as claimed inclaim 1, further comprising an electrical lamp for lighting said drum,said lamp being disposed between said instrument panel and said drum,said instrument panel being removable from the body of the electronicoven. .Iaddend..Iadd.
 14. A cooking time adjusting arrangement asclaimed in claim 1, wherein said drum is covered by a covering having anopening in register with said window portion and further comprising anelectrical lamp positioned behind said drum for illuminating said drum,rays of light emitted from said lamp being transmitted to said openingby being reflected by the inner surface of said covering..Iaddend..Iadd.
 15. The device of claim 1 wherein said rotatable drum iscoupled to said operating shaft and driven thereby synchronously withsaid pointer needle, information being arranged on said drum innumerical order according to required cooking times whereby said pointerwill be appropriately positioned for the information displayed..Iaddend..Iadd.
 16. A cooking time adjusting arrangement as claimed inclaim 1, wherein said pointer needle is coupled to said operating shaftby a cable and moves in response to rotation of said operating shaft,said pointer needle moving in parallel relation to the longitudinal axisof said drum along said window. .Iaddend. .Iadd.
 17. A cooking timeadjusting arrangement as claimed in claim 16, wherein a drive wheelmounted on said operating shaft and a plurality of idle pulleys, two ofsaid idle pulleys being positioned on opposite sides of said drive wheelare provided such that a first portion of said cable entering said drivewheel and a second portion of said cable emerging from said drive wheelare aligned in a straight line with respect to each other..Iaddend..Iadd.
 18. A cooking time adjusting arrangement as claimed inclaim 17, wherein said two of said idle pulleys are rotatably supportedby a fixed member such that said two pulleys are respectivelyfrontwardly and rearwardly displaced with respect to the plane of saiddrive wheel. .Iaddend..Iadd.
 19. A cooking time adjusting arrangement asclaimed in claim 16, wherein said pointer needle is connected with saidcable by means of a block slidably mounted on a guide rail, said blockhaving a member for securing said cable to said block at both endsthereof, both ends thereof projecting from said block in the directionof movement of said slidable block. .Iaddend..Iadd.
 20. A cooking timeadjusting arrangement as claimed in claim 16, wherein said cable hasboth ends connected by means of a tension spring and further including apair of projections extending from a fixed member within the stroke ofmovement of said tension spring for facilitating connection between saidends of said cable by means of said tension spring. .Iaddend..Iadd. 21.A cooking time adjusting arrangement as claimed in claim 8, wherein saiddrive wheel has one face formed with a hollow projection, the interiorof said hollow projection being formed with a plurality of pairs ofopposed protrusions for firmly securing a pin provided on the operatingshaft thereby permitting the drive wheel to be rigidly and firmlymounted in position on said operation shaft. .Iaddend..Iadd.22. Acooking time adjusting arrangement as claimed in claim 17, wherein saiddrive wheel is formed on its periphery with a notch and a pair ofprojections on both sides of said notch, each of said projectionsprojecting from the plane of said wheel in the direction parallel to thelongitudinal axis of said operating shaft. .Iaddend.